For the antireflection coating of surfaces, in particular of optical elements or displays, use is usually made of reflection-reducing interference layer systems containing a plurality of alternating layers composed of high refractive index and low refractive index materials. MgF2 with n=1.38 is currently used as material having a particularly low refractive index in the visible spectral range. The antireflection effect of conventional dielectric layer systems could be improved if materials having a lower refractive index were available.
The document EP 1791002 A1 discloses binding particles of MgF2 into amorphous silicon oxide in order to obtain a layer having an even lower refractive index.
Furthermore, the document EP 1403665 A2 describes binding hollow nanoparticles into an inorganic silicon oxide layer in order to produce a layer having a particularly low refractive index.
An alternative possibility for reducing the reflection of an optical element is known from the German patent document 10241708 B4. In this method, a nanostructure is produced at the surface of a plastic substrate by means of a plasma etching process, the reflection of the plastic substrate being reduced by the nanostructure. The antireflection structuring of an optical element by producing a nanostructure at the surface of the element has the advantage of obtaining low reflection over a wide incident angle range.